I was able to view all the sites on your account, the WordPress.com site and your two self-hosted sites with Jetpack enabled, over a WiFi connection.

From the way you’ve described the problem, it sounds like your Internet Service Provider that your wifi connects to may be having some issues connecting with WordPress.com (or your hosting provider on the self-hosted sites.) If it was a hosting-side problem, the site would also not load on mobile networks.

The next time you cannot connect to your site over wifi, would you please follow these steps to run a Traceroute?